Difference between TCP Listener and Socket

Question

As far as I know I can create a server using both TCPListener and Socket, so what is the difference between the two of them?

Socket

private Socket MainSock; MainSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); MainSock.Bind(new IPEndPoint(IPAddress.Any, port)); MainSock.Listen(500); MainSock.BeginAccept(AcceptConnections, new Wrapper()); 

TCPListener

    Int32 port = 13000;     IPAddress localAddr = IPAddress.Parse("127.0.0.1");     TcpListener server = new TcpListener(localAddr, port);     server.Start(); 

I'm really confused. The two of them listen for connections, so what is the difference between them?

Updated Code

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Net; using System.Net.Sockets; using System.Net.Security; using System.Security.Authentication; using System.Security.Cryptography.X509Certificates; using System.IO;  public class Wrapper {     public byte[] buffer;     public SslStream sslStream;     public object connector; }  public class Sock {     private Dictionary<string, byte> Connections;     public event Action<Wrapper> AnnounceNewConnection;     public event Action<Wrapper> AnnounceDisconnection;     public event Action<byte[], Wrapper> AnnounceReceive;     private Socket _sock;      private X509Certificate certificate = X509Certificate.CreateFromCertFile("exportedcertificate.cer");      public Sock(int port)     {         try         {             Connections = new Dictionary<string, byte>();             _sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);             _sock.Bind(new IPEndPoint(IPAddress.Any, port));             _sock.Listen(500);             _sock.BeginAccept(AcceptConnections, new Wrapper());         }         catch (Exception e)         {             Console.WriteLine(e);         }     }      private void AcceptConnections(IAsyncResult result)     {         Wrapper wr = (Wrapper)result.AsyncState;         try         {             wr.sslStream = new SslStream(new NetworkStream(_sock.EndAccept(result), true));             wr.sslStream.BeginAuthenticateAsServer(certificate, AcceptAuthenticate, wr);              _sock.BeginAccept(AcceptConnections, new Wrapper());         }         catch (Exception e) { Console.WriteLine(e); }     }      private void AcceptAuthenticate(IAsyncResult result)     {         Wrapper wr = (Wrapper)result.AsyncState;         try         {             wr.sslStream.EndAuthenticateAsServer(result);             if (wr.sslStream.IsAuthenticated == true)             {                 AnnounceNewConnection.Invoke(wr);             }         }         catch (Exception e) { Console.WriteLine(e); }     }      private void ReceiveData(IAsyncResult result)     {         Wrapper wr = (Wrapper)result.AsyncState;         try         {             AnnounceReceive.Invoke(wr.buffer, wr);         }         catch (Exception e) { Console.WriteLine(e); AnnounceDisconnection.Invoke(wr); }     } } 

Answer 1

TcpListener is a convenient wrapper for TCP communications. This allows you to use TcpClient for accepted connections--although you can accept sockets instead of clients to use Socket instead of TcpClient. You can do the same thing with Socket; but you have to deal with some of the TCP-specifics (like SocketType.Stream, ProtocolType.Tcp). TCP is a stream-based protocol and TcpClient recognizes that by letting you do stream communications by providing a stream with TcpClient.GetStream(). Socket is at a higher different level and needs to support many different protocols like UDP that aren't stream based.

TcpClient.GetStream returns a NetworkStream object that is suitable for SslStream; so, it should be much less work than using Socket directly. The documentation for SslStream details using TcpListener and TcpClient for SSL communications.

Answer 2

They're just different classes that do the same thing, written at different levels. Under the hood the TCPListener undoubtedly calls something very like your first Socket-based code. It;s just there to hide you from some of the gory details.